<%
'*****************************************************
'Description: sha1加密功能
'Copyright:Copyright(c)2012
'Company:204studio
'@author:klarkyang
'@version:1.0
'******************************************************
%>
<script language="javascript" type="text/javascript" runat="server">  
var hex_chr = "0123456789abcdef";
function hex(num)
{
var str = "";
for(var j = 7; j >= 0; j--)
str += hex_chr.charAt((num >> (j * 4)) & 0x0F);
return str;
}

/*
* Convert a string to a sequence of 16-word blocks, stored as an array.
* Append padding bits and the length, as described in the SHA1 standard.
*/
function str2blks_SHA1(str)
{
var nblk = ((str.length + 8) >> 6) + 1;
var blks = new Array(nblk * 16);
for(var i = 0; i < nblk * 16; i++) blks[i] = 0;
for(var i = 0; i < str.length; i++)
blks[i >> 2] |= str.charCodeAt(i) << (24 - (i % 4) * 8);
blks[i >> 2] |= 0x80 << (24 - (i % 4) * 8);
blks[nblk * 16 - 1] = str.length * 8;
return blks;
}

/*
* Add integers, wrapping at 2^32. This uses 16-bit operations internally
* to work around bugs in some JS interpreters.
*/
function safe_add(x, y)
{
var lsw = (x & 0xFFFF) + (y & 0xFFFF);
var msw = (x >> 16) + (y >> 16) + (lsw >> 16);
return (msw << 16) | (lsw & 0xFFFF);
}

/*
* Bitwise rotate a 32-bit number to the left
*/
function rol(num, cnt)
{
return (num << cnt) | (num >>> (32 - cnt));
}

/*
* Perform the appropriate triplet combination function for the current
* iteration
*/
function ft(t, b, c, d)
{
if(t < 20) return (b & c) | ((~b) & d);
if(t < 40) return b ^ c ^ d;
if(t < 60) return (b & c) | (b & d) | (c & d);
return b ^ c ^ d;
}

/*
* Determine the appropriate additive constant for the current iteration
*/
function kt(t)
{
return (t < 20) ? 1518500249 : (t < 40) ? 1859775393 :
(t < 60) ? -1894007588 : -899497514;
}

/*
* Take a string and return the hex representation of its SHA-1.
*/
function SHA1(str)
{
var x = str2blks_SHA1(str);
var w = new Array(80);

var a = 1732584193;
var b = -271733879;
var c = -1732584194;
var d = 271733878;
var e = -1009589776;

for(var i = 0; i < x.length; i += 16)
{
var olda = a;
var oldb = b;
var oldc = c;
var oldd = d;
var olde = e;

for(var j = 0; j < 80; j++)
{
if(j < 16) w[j] = x[i + j];
else w[j] = rol(w[j-3] ^ w[j-8] ^ w[j-14] ^ w[j-16], 1);
var t = safe_add(safe_add(rol(a, 5), ft(j, b, c, d)), safe_add(safe_add(e, w[j]), kt(j)));
e = d;
d = c;
c = rol(b, 30);
b = a;
a = t;
}

a = safe_add(a, olda);
b = safe_add(b, oldb);
c = safe_add(c, oldc);
d = safe_add(d, oldd);
e = safe_add(e, olde);
}
return hex(a) + hex(b) + hex(c) + hex(d) + hex(e);
}
</script>

